had better 是一个固定搭配,相当于一个情态动词。
1.had better后面必须跟动词原形。had better后跟动词原形(即不带to的不定式)，构成had better do sth.句型。这里的had不能用have来替换。
例句：You'd better go to hospital at once.你最好立即去医院看病。
2.主语不论是第几人称，句子不论是什么时态，都要用had better的形式。
例句：Now you(he，we) had better listen to the teacher.你(他，我们)现在最好听老师讲。
3.had better可用于的时态。
had better用于指现在。
例句：Now you had better listen to the radio.你现在最好听收音机。
had better用于指将来。
例句：You had better start tomorrow.你最好明天动身。
扩展资料：
1.have……do: have sb do sth让某人做某事
例句：I will have him cut my hair.
2.have……done: have sth done让某事被做;还有个意思是表示主语的坏遭遇;其实这个结构是由have sb do sth变过来的:have sth done by sb.
例句：I will have my hair cut by him.
3.have……doing: have sb/sth doing让某人/某物一直做……
例句：Don't have the horse running all the way.
4.have to不得不
5.have fun 玩得开心
6.have in mind 考虑
7.have got 拥有
8.have on 穿着 戴着
9.have a look 看一看
10.have no idea 一点也没听说过 一点也不知道
11.have access to 可以到达
12.have a good time 玩得痛快
13.have some food 吃点东西
had better 是一个固定搭配,相当于一个情态动词
had better do 最好做某事,后面跟动词原形
you had better go to school now.你现在最好去上学.
记住,不要用have代替had,因为它是一种固定搭配.本回答被提问者和网友采纳